1. Field of the Invention
The present invention relates to an improvement of a tilt cylinder device for an outboard motor.
2. Description of the Related Art
The state of the art is shown in Japanese Patent Application Publication No. 62-10876 (MARINE PROPULSION UNIT).
Such structure prevents excessive pressure load from being applied to a cylinder piston assembly or its hydraulic fluid circuit which tilts a propulsion assembly, when a marine propulsion unit collides against an obstacle in the water. As shown in FIGS. 1 and 2 of this publication, this conventional marine propulsion unit comprises, a member 13 mounted to a boat body 15, a swivel bracket 19 vertically rotatably mounted to the member 13, a propulsion unit assembly 17 mounted to the swivel bracket 19, an inclined cylinder piston assembly 33 having an inclined cylinder 35, an inclined piston 41 and a piston rod 43, provided between the member 13 and the swivel bracket 19, a pump 73 provided outside the inclined cylinder piston assembly 33 for supplying a pressurized fluid, a control valve 75 connected to the pump 73 for controlling a flow of the pressurized fluid which is to be supplied to the inclined cylinder piston assembly 33, and an automatic releasing assembly 151 for gradually constricting the inclined cylinder 35 which lowers the propulsion unit assembly 17 to the original position, when the propulsion unit assembly 17 collides against an obstacle in the water and is moved upward.
In the above prior art, the pump 73, since the control valve 75 and the automatic releasing assembly 151 are provided outside the inclined cylinder piston assembly 33 as separate members, it is necessary to secure a large space between the boat body 15 and the propulsion unit assembly 17, and there is an undesirable probability that a handling efficiency of the propulsion unit assembly 17 may be reduced.